(1) Field of the Invention
This invention relates to compressing natural gas for transportation in pipe lines. Managers of compression units have ordinary skill in this art.
(2) Description of the Related Art
The general practice of transporting natural gas from a well includes compressing the gas from the pressure it has at the well head to a high pressure for transportation to the point of usage. The equipment to perform this task is usually a liquid ring compressor or a screw compressor which are widely used and well known in the art. Characteristic of these compressors is that the compressor has an oil seal.
It is necessary in the operation of an oil seal compressor to cool the oil. Some of the oil will mix with the compressed gas at high temperatures. The oil is separated from the compressed gas before the gas enters the pipe line. It is standard practice in compression units to have a mechanical refrigeration unit to cool the seal oil after it has been separated from the compressed gas and before it is reintroduced into the compressor.
The refrigeration units add to the capital investment and the operation increase the cost of operating the compression unit. Also it is an additional piece of machinery which requires the normal maintenance and the other operation attention of personnel.
(1) Progressive Contribution to the Art
According to this invention the hot separated seal oil is fed through a heat exchanger which transfers the heat of the oil into the cold gas coming from the well. The natural gas is cold because of its expansion from the deposit within the earth to the intake of the compressor.
The oil is cooled in the exchanger without mechanical machinery.
The oil is separated from the gas in part by slinging the oil outward in a centrifugal fashion.
The heat transferred from the seal oil to the gas entering the compression increases the gas temperature. This increase in temperature will require more energy to compress the gas to the pipeline pressure. However the ability to avoid the initial cost of the refrigeration equipment and the normal expense necessary for workman to monitor the refrigeration equipment makes the operation advantageous over mechanical refrigeration. There will also be a slight pressure drop of the gas from the well because of the turbulence caused by the gas circulating in the heat exchanger. However; the advantages out weigh this disadvantages also.
(2) Objects of this Invention
An object of this invention is to simplify the process of cooling seal oil at gas compression units.
Another object of this invention is to use the natural resulting low temperature of the gas entering the compressor as a source of cooling for the seal oil used in the compressors.
Another object is to simplify the separation of the oil from the compressed gas.
Further objects are to achieve the above with devices that are sturdy, compact, durable, simple, safe, efficient, versatile, ecologically compatible, energy conserving, and reliable, yet inexpensive and easy to manufacture, install, operate, and maintain.
Other objects are to achieve the above with a method that is rapid, versatile, ecologically compatible, energy conserving, efficient, and inexpensive, and does not require highly skilled people to install, operate, and maintain.
The specific nature of the invention, as well as other objects, uses, and advantages thereof, will clearly appear from the following description and from the accompanying drawings, the different views of which are not necessarily scale drawings.